Page:On the economy of machinery and manufactures - Babbage - 1846.djvu/188

154 I believe it may be considered as a fair approximation. In the course of my inquiries I have been favoured with another list, in which many of the same articles occur; but in this last instance the prices quoted are separated by an interval of twenty years. It is extracted from the books of a highly respectable house at Birmingham; and the prices confirm the accuracy of the former table, so far as they relate to the articles which are found in that list.